Semiconductor Fabs Generate Some of the World's Most Complex PFAS Waste - and the Tools to Handle It Are Still Catching Up

A single large semiconductor fabrication facility can generate thousands of cubic meters of contaminated wastewater every day. That water carries a mixture of per- and polyfluoroalkyl substances - PFAS, often called forever chemicals - along with solvents, metals, and salts from hundreds of integrated manufacturing steps. Managing that waste stream is one of the more demanding environmental engineering challenges the electronics industry faces, and demand for chip manufacturing is accelerating.

A review published in Environmental Science and Technology takes stock of where the science and technology currently stand, and where the field needs to advance. The paper emerged from a National Science Foundation-funded workshop held in August 2024, which brought together experts from academia, industry, and government. It synthesizes findings from more than 160 published studies alongside insights from that workshop.

Why Semiconductor PFAS Is Different

PFAS compounds are central to chipmaking because their chemical properties - extreme stability, low surface tension, resistance to heat - make them ideal for processes like photolithography and etching. There is no simple substitute for many of these applications. The same properties that make them useful in manufacturing also make them persistent in the environment and resistant to conventional water treatment.

Compounding the technical challenge is a knowledge gap. Many of the specific PFAS formulations used in chipmaking are proprietary trade secrets. Researchers often cannot identify exactly which compounds they are working with, which makes it harder to select appropriate treatment strategies. Short-chain and ultrashort-chain PFAS variants common in semiconductor waste are especially difficult to capture with conventional methods designed for longer-chain compounds.

"Managing the waste from these facilities is a massive undertaking," said Xiao Su, a professor of chemical and biomolecular engineering at the University of Illinois Urbana-Champaign. "A single large factory can produce thousands of cubic meters of wastewater per day, containing a soup of diverse PFAS mixed with various solvents, metals and salts."

Three Priority Areas

The review identifies three areas that need simultaneous development: improved monitoring, effective separation, and safe destruction of PFAS compounds.

On monitoring, the authors highlight advanced tools - including AI paired with high-resolution mass spectrometry - that could help identify where specific PFAS compounds originate in production processes and how they transform as waste moves through treatment systems. Without knowing what is in a waste stream and where it comes from, selecting the right intervention is largely guesswork.

For separation, the challenge is concentrating PFAS from dilute waste streams into a form that can be treated or destroyed. Conventional adsorbents and membranes developed for municipal water systems often fail against the complex matrices in industrial semiconductor waste. Novel electrochemical approaches, specialized adsorbent materials, and membrane technologies are among the more promising candidates, but most still require adaptation for industrial-scale deployment.

Destruction is where the field faces its most fundamental challenge. PFAS bonds are exceptionally strong - that is precisely why the compounds do not break down in the environment. Technologies such as plasma discharge and electrochemical oxidation can cleave those bonds, but they typically require significant energy input and may generate byproducts that need their own management.

The Integration Problem

Even promising technologies face a structural obstacle. Semiconductor fabrication is extraordinarily complex and tightly optimized. A typical fab runs hundreds or even a thousand integrated manufacturing steps. Any treatment system introduced into that environment needs to fit without disrupting production.

"There's also this challenge of how everything is so integrated and how many steps it has," said Devashish Gokhale, a postdoctoral researcher at Illinois and lead co-author. "If you develop new treatment solutions, they need to be able to fit inside this complex operation without affecting everything else that is highly optimized."

This constraint means that theoretical solutions developed in academic labs face a significant translation challenge. Technologies that work well in controlled experimental settings may prove difficult or prohibitively expensive to integrate into working fabs where production downtime carries enormous cost.

The Regulatory and Collaboration Gap

The review is candid about factors that extend beyond technical fixes. Progress requires clearer understanding of where PFAS regulations are headed, so that industry investments in treatment infrastructure align with what will eventually be required. It also requires access to real industrial waste streams for laboratory research, something that proprietary concerns have often blocked. Scaling up technologies from lab demonstrations to industrial settings requires partnerships spanning academia, government, and the companies actually running the fabs.

The broader context matters. The global semiconductor industry is expanding rapidly, driven by demand for AI infrastructure and advanced electronics. New fabs are being built in the United States under the CHIPS Act and in other countries under similar industrial policy frameworks. PFAS waste volumes will grow alongside that expansion unless treatment infrastructure develops in parallel.

"The ultimate goal is to integrate these tools into compact, cost-effective systems that can be implemented in either existing or future space-constrained factories," Su said. "By fostering partnerships between academia, government and industry, the sector aims to reach a zero-discharge future that supports both technological advancement and environmental safety."

The review was led by Gokhale, Gabriel Cerron-Calle of Arizona State University, and Mitchell Kim-Fu of Oregon State University, and is available at doi.org/10.1021/acs.est.5c10109.